Looking at the far side of the Moon
September 2nd 2007 07:04
Category: No Category
I must admit I am a complete Lunarphile ( or lunatic well that’s is another story) the Moon never fails to amaze me. It doesn't mat¬ter if it's a rising full moon bathed in golden light rising over the horizon or a close up telescopic view of its battered face I find the Moon ir¬resistible. Whenever, it's up in the sky, you can usually find me eagerly setting up my telescope in the hopes of seeing something new. And one of my favourite places to look is the far side of the Moon. I can almost hear you say: "Wait a minute everyone knows that you can only see one side of the Moon' that’s true but thanks to something called libration you can from time to time see a bit of the "far side that is, the hemisphere that’s hidden from our view. How's that possible?
The darkside of the Moon shows more craters and less "seas" because it is thought that the darkside of the Moon has a thicker surface crust.
Notwithstanding its constantly changing phases, the most ob¬vious aspect of the Moon's appearance is that it always presents the same face toward Earth. You might think that having just one hemisphere in view must mean that the Moon doesn’t rotate on its axis at all. But you can prove otherwise by walking in circle around a basket ball , place a large basketball on a table walk around the table while facing inward, keeping you’re on the ball in front of you. Even though the ball is always in view, you see the world beyond it slowly spin by When you've (completed one "orbit," you'll have turned through an entire 360 rotation.
In like fashion, the Moon takes the same amount of time to spin once on its axis as it does to travel around Earth: 27.3 days, this coincidence is known: synchronous rotation, and it's actually a common situation among large satellites in our solar system.
How did this come about? The short answer is this phenomenon is caused by "tidal friction” when it formed billions of years ago, the Moon was much closer to Earth, which created strong tides on both bodies the Moon raises tides in Earth's oceans. Earth’s gravity subtly distorted the lunar interior over a time period of many thousands of years the tidal tug of war slowed the Moon's rotational rate until it eventually matched its orbital period.
This sidereal period is measured with respect to the Moon's among the stars. But since Earth is also moving in its orbit, the position gradually shifts eastward among the stars. So the Moon takes a little longer to catch up to the Sun, requiring 29.5 days (called a synodic period) to complete its cycle of phases from new Moon to Moon.
The Moon is in synchronous rotation with Earth , meaning that it keeps the same face turned to the Earth at all times. This synchronous rotation is only true on average because the Moon's orbit has definite eccentricity. When the Moon is at its perigee,(Moon closest approach to the Earth.) its rotation is slower than its orbital motion, and this allows us to see up to an extra nine degrees of longitude of its East (right ) far side. Conversely, when the Moon reaches its apogee, its rotation is faster than its orbital motion and reveals another eight degrees of longitude of its West (left) side.
This is called longitudinal libration. It is possible to see a portion of the darkside of the Moon best seen through a telescope or you can document it with a photograph.The photograph on the right reveals more of Mare Marginis.
Apollo 16 image of the farside of the Moon
The darkside of the Moon shows more craters and less "seas" because it is thought that the darkside of the Moon has a thicker surface crust.
Notwithstanding its constantly changing phases, the most ob¬vious aspect of the Moon's appearance is that it always presents the same face toward Earth. You might think that having just one hemisphere in view must mean that the Moon doesn’t rotate on its axis at all. But you can prove otherwise by walking in circle around a basket ball , place a large basketball on a table walk around the table while facing inward, keeping you’re on the ball in front of you. Even though the ball is always in view, you see the world beyond it slowly spin by When you've (completed one "orbit," you'll have turned through an entire 360 rotation.
How did this come about? The short answer is this phenomenon is caused by "tidal friction” when it formed billions of years ago, the Moon was much closer to Earth, which created strong tides on both bodies the Moon raises tides in Earth's oceans. Earth’s gravity subtly distorted the lunar interior over a time period of many thousands of years the tidal tug of war slowed the Moon's rotational rate until it eventually matched its orbital period.
This sidereal period is measured with respect to the Moon's among the stars. But since Earth is also moving in its orbit, the position gradually shifts eastward among the stars. So the Moon takes a little longer to catch up to the Sun, requiring 29.5 days (called a synodic period) to complete its cycle of phases from new Moon to Moon.
The Moon is in synchronous rotation with Earth , meaning that it keeps the same face turned to the Earth at all times. This synchronous rotation is only true on average because the Moon's orbit has definite eccentricity. When the Moon is at its perigee,(Moon closest approach to the Earth.) its rotation is slower than its orbital motion, and this allows us to see up to an extra nine degrees of longitude of its East (right ) far side. Conversely, when the Moon reaches its apogee, its rotation is faster than its orbital motion and reveals another eight degrees of longitude of its West (left) side.
Depending on the rotation of the Moon you are able to see the farside at some point during the month see right image
This is called longitudinal libration. It is possible to see a portion of the darkside of the Moon best seen through a telescope or you can document it with a photograph.The photograph on the right reveals more of Mare Marginis.
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Comment by Tracy
Movies and Life
Your blog is fascinating...
Tracy
Comment by CarlCan
Astroearth
Camera Sense
I try to keep it interesting
Comment by Tracy
Movies and Life
Comment by Mountain Fog
Infognito
Screen Trek
QUOTE ME NO QUOTES!
can you explain to everyone why the moon is hollow? has NASA established why yet?
fog
Comment by CarlCan
Astroearth
Camera Sense
Is the Moon hollow? At the moment it is still a theory and no conclusive proof to say that the moon is hollow. (green cheese perhaps teehee)
There are parts of the moon that may have rock structures underneath the Moon’s surface that are more “pourus” The fact that the seismic activity recorded by the Apollo missions may not be accurate.
We already know the mass of the Moon and we know the size of the Moon so can calculate the density of the Moon and given the measurements and the gravitation force on the Moon would not suggest that the Moon was hollow. I am not a geologist I am only applying fundamental mathematical calculations and not studying the Moon’s rock morphology.
There are publications referring to the Moon “ringing” like a bell when hit buy an object like a meteorite or parts of the Apollo rocket boosters hitting the Moon’s surface. This produced a seismic event that was recorded by the instruments left on the Moon’s surface following the Apollo missions.
Applying laws of physics hitting an object will produce a resonance or “ringing” you also need to remember that an object hitting the moon may cause a fundamental resonance on the Moon matching the Moon’s resonance and associated harmonics whereby producing a ring. The evidence of ringing does not prove that the Moon is hollow just resonate.
Comment by Mountain Fog
Infognito
Screen Trek
QUOTE ME NO QUOTES!
My father was an exploration geologist, and this fact rather amazed him. He said the moon would have to be hollow for that to happen for such an extended period of time...and he didn't take into account the green cheese, of course!
cheers
fog
Comment by Mountain Fog
Infognito
Screen Trek
QUOTE ME NO QUOTES!
OH MY GAWD IT'S A DEATH STAR!!!!!!!!!
fog